Recent research has demonstrated that priming and recognition memory performance are not independent as traditionally thought. Evidence is accumulating suggesting that information recognized in great detail (recollected) also has higher levels of priming (Sheldon & Moscovitch, 2010; Turk-Browne, Yi, & Chun, 2006). The purpose of this dissertation was to delineate the conditions under which recognition processes (estimates of recollection and familiarity) are associated with priming, and how this changes with age. Results from a systematic crossing of level of encoding (deep versus shallow) with type of priming task (conceptual versus perceptual) suggests that the relation between priming and recognition is determined by the nature of the encoding task. Under deep encoding conditions, a greater magnitude of priming—both perceptual and conceptual—was related to subsequent recollection but only amongst younger adults. Under shallow encoding conditions, perceptual priming performance was related to subsequent familiarity in both younger and older adults. Taken together, this series of experiments suggests that the processing mode engaged during encoding dictates which processes will be engaged at retrieval (a recollection-based process, or a familiarity-based process; Henke, 2010). These findings also suggest that both recollection and familiarity have rapid and unconscious aspects that are measurable through behavioural priming tasks, aligning with a recently proposed model suggesting recollection is characterized by a two-stage process, an early, relatively automatic and unconscious stage and a later, controlled and conscious stage (Moscovitch, 2008). It is suggested that the rapid, unconscious aspects of recollection may decline across the lifespan, while the rapid, unconscious aspects of familiarity stay intact with age.

Rapid compensatory reach-to-grasp reactions are prevalent and functionally important responses to instability. The need to react very rapidly (to prevent falling) imposes temporal constraints on acquisition and processing of the visuospatial information (VSI) needed to guide the reaching movement. Previous results suggested that the CNS may deal with these constraints by using VSI stored in memory proactively, prior to perturbation-onset; however, the extent to which online visual control is necessary or sufficient to guide these reactions has not been established. Furthermore, the influence of memory-decay and concurrent cognitive-task on the performance of these reactions has not been examined. This Thesis employed a novel paradigm wherein the participant is stationary and a motor-driven handhold is positioned unpredictably in front of the participant for each trial. Reach-to-grasp reactions were evoked in healthy young and older adults by sudden unpredictable antero-posterior platform translation (barriers deterred stepping reactions). Liquid-crystal goggles were used to occlude vision either before (recall-delay time=0s/2s/5s/10s) or after perturbation-onset to force reliance on either stored- or online-VSI, respectively. Participants performed a spatial- or non-spatial-memory task during the delay-time in a subset of trials. When forced to rely on stored-VSI, all participants showed reduction in reach accuracy; however, a tendency to undershoot the handhold was exacerbated in the older adults. Forced-reliance on online-VSI led to similar delays in all participants; however, the older adults were more likely to reach with the “wrong” arm or raise both arms. Comparison with normal-VSI trials suggests that both sources of VSI are utilized when grasping the movable handhold for support, with stored-VSI predominating during initiation/transport and online-VSI contributing primarily to final target acquisition/prehension. In terms of recall-delay, both age groups showed comparable reduction in medio-lateral endpoint accuracy when delay-time was longest. Moreover, both cognitive tasks had similar (slowing) effects in both age-groups, suggesting these effects were related to generic attentional demands. However, the older-adults also showed a dual-task interference effect (poorer cognitive-task performance) that was specific to the spatial-memory-task. Further research is needed to establish whether interventions aimed to improve visual/cognitive processing speed, visuospatial memory, and/or attention capacity can reduce risk of falling among senior populations.

Introduction: A common disorder arising most frequently after a left hemisphere stroke is limb apraxia. Limb apraxia is a deficit of skilled movement, such as performance of activities of daily living (ADLs), that is not a result of primary motor or sensory impairments, or deficits in motivation, memory, or comprehension (De Renzi, 1990). Currently, clinical neuropsychological assessment of apraxia relies largely on qualitative analyses of gross movements during the performance of activities of daily living in two task conditions (pantomime and tool). Further, apraxic patients often perform ADLs with their non-dominant limb to avoid often-present right-hand hemiparesis, but the assessment does not adequately account for this. Thus, it is unclear whether movement deficits are due to non-dominant limb use or limb apraxia. Moreover, it is not known how different task conditions and aging influence the performance of ADLs in healthy populations, as well as manual asymmetries. Purpose: The purpose of this thesis was to: 1. determine if age affects the magnitude of manual asymmetry in the performance of two ADLs (drinking water from a cup and slicing a loaf of bread with a knife); 2. determine if different task demands (pantomime and tool condition) affect magnitude of manual asymmetries during the performance of ADLs; and 3. determine if aging affects how task demands are expressed during the performance of ADLs. Methods: Fifty healthy right-hand dominant (as determined via Waterloo Handedness Questionnaire) younger and older adults participated in this study. A grooved pegboard task was completed by all participants prior to performance of the two ADLs using motion tracking. Upper limb movements (dominant and non-dominant limb) were captured at 60 Hz via a motion capture system (Vicon, Oxford, UK). Participants performed two task conditions: 1) pantomime (pretending to perform an ADL without holding the tool); and 2) tool (pretending to perform an ADL while holding the tool) in two ADLs: drinking water from a cup and slicing a loaf of bread with a knife. Each ADL was performed six times by both limbs. ADLs and limbs were randomized, while task conditions were blocked randomized between participants. Results: Overall, this study found that aging slows down motor performance on the Grooved Pegboard task, as well as the performance of both ADLs. Manual asymmetries were task dependent. The cup and knife ADL were both characterized by larger manual asymmetries in older adults relative to the younger adult group, particularly in terms of angular movement. Further, it was found that task demands were expressed differently in older adults relative to younger adults, with the tool condition yielding performance improvements in both groups. Conclusions: Despite the previous research, which has shown that manual asymmetries are reduced in older adults during the performance of motor tasks, this investigation points to the opposite during the performance of activities of daily living. Aging appears to increase the degree to which manual asymmetries are expressed. Further, aging also appears to play a role in the change in temporal and angular aspects of movement during the performance of ADLs in different task conditions. The degree to which task demands as reflected in the two task conditions improve or impair performance in healthy populations should be taken into consideration when evaluating ADL performance in patients with limb apraxia. In accordance with the previous research on aging, this study has shown that upper limb movements become slower as individuals age. Kinematic relationships presented in this study provide researchers and clinicians with an insight into how manual asymmetries, aging and different task demands come into play during the performance of one cyclical and non-cyclical task.

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Several genes involved in the regulation of apoptosis can influence longevity. Although observations in several different systems imply that apoptosis and aging are closely linked, the relationship between the two remains largely unknown. In this study, Drosophila melanogaster was used as a model organism to explore the relationship between aging and apoptosis regulation. Apoptosis was investigated using two apoptotic hallmarks: caspase activity and DNA fragmentation. The results showed that apoptosis occured in adult flies at all ages and the changes in apoptosis associated with aging were linked to physiological age and were tissue-specific. During normal fly aging, apoptosis increased gradually within the muscle and was activated in the fat of old flies. However, neither of the two apoptotic signs were shown in the nervous system. The analysis of the apoptotic response to starvation and oxidative stress suggested that the increased apoptosis in muscle resulted from the accumulation of oxidative damage associated with aging. Once the presence of apoptosis during Drosophila aging was confirmed, the expression of anti-apoptotic genes was manipulated in specific tissues to examine the impact of a localized alternation of apoptosis on aging. The overexpression of anti-apoptotic genes in muscle extended Drosophila mean and maximum life span up to 99% and 65%, respectively. This extension was mediated by apoptosis inhibition using the detection of caspase activity and DNA fragmentation. In addition, the long-lived animals exhibited increased resistance to oxidative stress and preserved flight ability. Overall this study establishes that muscle apoptosis limits life span and participates in sarcopenia. This finding may have applications in the development of interventions to improve the life quality of elderly human. / Thesis (Ph.D, Biology) -- Queen's University, 2008-10-27 00:24:02.204

This thesis examined the effect of age on sexually offensive behaviour. Research has noted both an increase in the average age of incarcerated offenders and that a higher percentage of older offenders are incarcerated for sexual offences than are younger offenders. Older sexual offenders were initially compared with younger offenders on offender and offence characteristics and these analyses revealed that older sexual offenders had a higher incidence of male victims, a younger victim age, and more intra-familial victims. Phallometric assessments of all sexual offenders were then examined to see whether sexual deviance may account for the differences found between older and younger sexual offenders in victim age and gender. These analyses revealed that the oldest and youngest offenders were more deviant than middle-aged sexual offenders and that the sexual interests of older offenders were more commonly for females. Finally, all subjects were classified as either Historical (offending had ceased, without judicial intervention, at least 7 years prior to incarceration), First-time (incarcerated for a recent sexual offence and no history of sexual offending), or Recidivist sexual offenders (currently incarcerated for a sexual offence and have at least one prior sentencing date for any sexual offence): age accounted for 12% of the variance in categorisation. Fifty-five percent of the sexual offenders age 60 years or more were found to have committed and ceased their offending at least seven years prior to incarceration (i.e., were Historical offenders). The percentage of Recidivist offenders remained relatively consistent across age groups at about 20%. No difference was found in phallometrically assessed sexual deviance between the groups of older offenders. / Thesis (Ph.D, Psychology) -- Queen's University, 2010-07-29 11:40:51.234

The proportion of elderly individuals in society is increasing dramatically, leading to an increase in the prevalence of age-related neurological disorders that affect the function of the frontal lobes and overall movement control. This thesis aims to evaluate ‘executive control’ and the underlying brain changes in normal versus abnormal aging processes using saccadic eye movement tasks. Tasks performed by subjects that probe executive control consist of antisaccades (generate a voluntary eye movement after inhibiting an automatic movement to a visual stimulus), and memory-guided saccades (generate eye movements to three previous remembered visual stimuli in the same sequence they were presented). Both of these types of saccades require good functioning behavioural control, which is subserved by areas in the prefrontal cortex. This thesis specifically characterizes the changes in oculomotor control related to aging, Huntington’s disease, mild cognitive impairment (amnestic), and Alzheimer’s disease. We also specifically examine the neural mechanisms related to behavioural control in the antisaccade task in aging. Together, the conclusions drawn from this thesis reveal that specific areas in the prefrontal cortex are involved in executive dysfunction in both normal and abnormal aging, but the patient groups studied have provided new understanding that different underlying brain substrates may be altering function in the frontal cortical areas, such as the basal ganglia and the hippocampus. / Thesis (Ph.D, Neuroscience Studies) -- Queen's University, 2011-04-28 13:44:32.25

The demand for home care increased dramatically in Canada in the past decade. This was because more patients were discharged from hospital, more emphasis was put on health care at the home and community levels, the continuing aging of the population, advancements in technology, and the adoption of a more cost-effective strategies. Though home care is still not a part of Canadian Health Act (CHA) and there are no national regulations for home care, people value the significance of home care. Home care is now one of the fastest growing sectors in Canada’s health care system. With a focus on the elderly population in the province of Ontario, this thesis uses data from the Canadian Community Health Survey (CCHS cycle 1.1, 2.1 and 3.1) to examine utilization patterns of home care considering social and geographical factors, the variation within home care service provision, and unmet home care need. The major findings of the thesis are that seniors with poorer health status, older age, female, with lower household incomes, marital status widowed/separated/divorced/single/never married, and living in urban areas are more likely to use home care. At the same time, seniors who are older, with poorer health status, and suffering from chronic condition are in a more vulnerable position to receive the home care they need. A large amount of responsibility was shifted to informal caregivers due to the budget constraints and the policy bias of the government. Access to home care is unequal on a geographical scale. Seniors living in rural and remote areas tend to have more unmet home care needs than seniors living in urban areas. People living in rural northern regions in Ontario have the least access to home care. Also, seniors living in urban areas have a greater chance of getting government provided care than those living in rural areas. Overall, under the current managed competition model of home care in Ontario, unequal accessibility, insufficient services, an excessive burden on informal caregivers are observed. / Thesis (Master, Geography) -- Queen's University, 2011-05-21 00:10:26.287